Barnaby is the youngest gorilla in his family and the first born in Roxbury Zoo, making him a hit with zoo visitors. The sign outside his den announces that Barnaby is "Number One!" Between adventures with his brother and special attention from just about everyone, Barnaby thinks life is perfect. But when another baby gorilla arrives, Barnaby's sign is replaced with one for her. On top of that, she seems to steal his spotlight. What will make Barnaby special when he's no longer what draws the crowds?